The invention relates to the selection of xe2x80x9cdrag reducer additivexe2x80x9d removal agents, and to the detection and/or removal of xe2x80x9cdrag reducer additivexe2x80x9d (DRA) from liquid hydrocarbon fuels.
In order to move fluid through pipelines, into or out of wells, or through equipment, energy must be applied to the fluid. The energy moves the fluid, but is lost in the form of friction. This frictional pressure drop, or drag, restricts the fluid flow, limiting throughput and requiring greater amounts of energy for pumping.
Materials can be added to flowing fluids in order to reduce the energy lost due to friction, or drag, thus permitting the movement of more fluid at the same differential pressure. The resulting reduction in frictional pressure drop improves pumping efficiency, lowers energy costs, and increases profitability. Materials for reducing drag in flowing fluids are generally known by the generic names xe2x80x9cflow improverxe2x80x9d or xe2x80x9cdrag reducer additivexe2x80x9d (sometimes referred to as xe2x80x9cDRAxe2x80x9d).
Unfortunately, whether in the virgin form or in the sheared or partially sheared form, and despite the fact that it is intentionally added to certain fuels, drag reducer additive nonetheless is a xe2x80x9ccontaminantxe2x80x9d in liquid hydrocarbon fuels, and has the potential to cause a number of problems. For example, the presence of drag reducer additive in motor gasoline, even in the sheared form, has caused increased intake valve deposits, plugging of fuel filters, and increased combustion chamber deposits. In diesel fuels, drag reducer additive may cause plugging of fuel filters and strainers and increased fuel injector deposits. Drag reducer additive is prohibited in aviation turbine fuels, although it has been observed as a contaminant due to accidental addition or other non-intentional means. The presence of drag reducer additive in aviation turbine fuel may result in downgrading of the entire batch to non-aviation kerosene or diesel fuel, both of which generally have less market value.
Viable methods of detecting and quantifying drag reducer additive in liquid hydrocarbon fuels commonly employ gel permeation chromatography, which is time consuming and expensive. Because of this, contaminated liquid hydrocarbon fuels often are used, despite the potential problems if drag reducer additive is present. Contaminated aviation turbine fuels may be diverted to other uses or returned to a refinery for reprocessing, either of which results in additional expense. Methods are needed to easily and inexpensively select materials that are capable of testing for the presence of drag reducer additive and/or capable of removing drag reducer additive from liquid hydrocarbon fuels.
Methods are provided for selecting one or more effective removal agents and using said agents to substantially reduce the concentration of drag reducer additive in a liquid hydrocarbon fuel.